The invention relates to steam turbine generators, and more specifically to the systems used to create superheated steam for a steam turbine generator.
In a typical steam generation system for a steam turbine generator, water is first supplied to a water heater, and the heated water is then supplied to a boiler. The boiler boils the water to generate steam. The steam is provided to a superheater, which then superheats the steam. The superheated steam is passed on to the steam turbine.
The temperature of the boiler is regulated by the fact that water is always present in the boiler. So long as water is present, the boiler never overheats.
However, the superheater controls its internal temperature, in part, by outputting the superheated steam. In other words, if one attempts to limit the output flow rate of the superheated steam from the superheater, the superheater can become overheated.
One can attempt to control the temperature of the superheater by controlling the amount of combustible materials or the amount of electricity provided to the superheater. However, the superheater must also be allowed to output superheated steam at whatever rate is necessary to control the temperature of the superheater on a moment-to-moment basis. As a result, the superheated steam generated by the superheater is often output at a temperature which is greater than the temperature which is optimal for the steam turbine. In some instances, the superheated steam can be at a temperature well above what the steam turbine can withstand.
In recognition of these facts, a typical steam generation system will include attemporators to cool the superheated steam output by the superheater before it reaches the turbine. In a typical attemporator, water is simply sprayed into the superheated steam to cool the superheated steam. While this is effective at reducing the temperature of the superheated steam to a temperature which is optimal for the steam turbine, the use of water in the attemporator to cool the superheated steam basically represents wasted heat. In other words, the use of an attemporator results in an inefficiency or energy loss within the system.